The Kill Factor by Ben Oliver

A brand-new gameshow that offers young criminals the chance at freedom has been greenlit. Little do they know, winning is their only chance at survival. A captivating examination of the dark truths around the criminal justice system, Ben Oliver, critically acclaimed author of The Loop trilogy, delivers an action-packed thrill ride with deadly high stakes. Fifty contestants. Five mental and physical challenges. One winner.
In a near-future where a virtual currency of digital content fuels a fame-hungry society, a brand-new experiment that combines social media and reality TV has been greenlit.
Voted on, and contestants are sent to a maximum-security reform camp on an island where they can have no contact with the outside world. To lose means prison. But to win is to be free. The most popular young offender with the most upvotes by the end is given both a second chance in society and a cash prize.
This kind of money could mean everything to Emerson and her family who live in the Burrows, one of the subterranean villages where the government have buried affordable housing. It's more than freedom. It could mean the chance to change her family's circumstance and finally find a place in the society they've never been allowed into.
But what Emerson doesn't know, what the viewers don't know, is that the prison on the island is empty. Those who lose, those who are voted off aren't incarcerated. Each challenge will leave more and more contestants to die. And the only choice they have is to win over viewers before it's too late.